The Heavens’ Locks and Crown
The moon wanes to last-quarter Tuesday, rising more than a half-hour later each night, providing an increasingly darker backdrop for sky-watching.
As the evening sky begins to darken, the first lights to appear are the planets Venus and Jupiter high in the west. Then you might notice golden Saturn aglow in the southeast. The next brightest object to appear is Arcturus, almost directly overhead.
Arcturus is the third brightest star in the heavens and is the lead star in the constellation Boötes. It is a red giant 36 light years away burning more than 100 times brighter than our sun. Its name is derived from the Greek word Arktouros, meaning guardian of the bear. Boötes follows Ursa Major along the ecliptic, while behind it is the constellation Hercules. Closer to either side of Arcturus, however, are two lesser-known constellations.
To the east of Boötes shines a semi-circle of severn stars, Corona Borealis, the northern crown. By about 11pm, this constellation is almost directly overhead. In Greek mythology, this is the crown Dionysus gave to his bride Ariadne. Celebrating after their wedding, Dionysus threw the crown into the sky, where the jewels turned into stars and the crown became a constellation. The lead star in Corona Borealis is Gemma, almost as bright as the North Star.
To the west of Arcturus is Coma Berenices, or Berenice’s Hair, most notable by three not-so-bright stars making a 90-degree angle. The legend of this constellation dates back to Queen Berenice II of Egypt, whose husband Ptolemy III Euergetes was away in battle. Praying to the goddess Aphrodite, Berenice swore to cut off her long, blonde hair if Ptolemy survived. Upon his return, the queen kept her word and placed her locks on an altar in Aphrodite’s temple. The next morning the hair was gone: the goddess of love was was so pleased with Berenice’s beautiful hair that she placed it forever in the heavens.
Venus is at its best this week, Saturday reaching greatest eastern elongation — or in layman’s terms, its farthest from the sun, 45 degrees as seen from our earthbound vantage, and thus at its highest point in our sky. As the sun sets, look for the Evening Star high in the west. Hereafter, Venus ever so slowly inches toward the setting sun. By mid-August, Venus disappears behind the sun, reappearing in the pre-dawn sky a couple weeks later.
Jupiter shines a dozen degrees to the upper left of Venus. The two planets are closing in on each other on the way to a close conjunction at the end of the month.
Sunset reveals Saturn in the southeast, and by midnight it is high in the south. Even a modest telescope will reveal the planet’s famous rings, which are right now tilted at their best angle for viewing. Roughly 10 degrees below Saturn is orange Antares, the lead star in the constellation Scorpius.